Dengue is terrible disease spread by a species of mosquito called Aedes aegypti.

By the early 2000s, the scientific community had been trying and failing at a vaccine for years, when a scientist named Scott O’Neill had an idea: What if instead of vaccinating the people, we treated the Aedes aegypti mosquito?

Most insects contain bacteria called Wolbachia. But the Aedes aegypti does not, and O’Neill believed that by introducing Wolbachia to the Aedes, he could shorten the mosquito’s lifespan, killing the insect before it had time to transmit dengue.

It was longshot R&D, and at first, it looked like it wouldn’t work. The Wolbachia wasn’t killing the mosquitos or shortening their lifespan. But then O’Neill realized it was doing something just as good: It made it impossible for Aedes to transmit dengue.

Today, countries like Indonesia are benefiting from this research. A study there found that in places with the Wolbachia mosquitos, dengue had virtually disappeared.

Individual mesh cubes are home to 1,000-1,500 mosquitoes at this World Mosquito Program research lab.

A health worker prepares a vaccine during a meningitis vaccination campaign in Kaolack, Senegal.

In 1996 and 1997, the largest meningitis epidemic in recorded history swept across the middle of the African continent. Meningitis is a terrifying and painful disease; of 250,000 people who fell ill, 25,000 died, and another 50,000 were left with permanent, debilitating injuries. Public health leaders on the continent pushed hard to address the crisis, and by the end of 2000, they were collaborating with WHO and PATH to create the Meningitis Vaccine Project (MVP), whose goal was to improve on the inadequate meningitis vaccine that existed at the time.

Early on, MVP started looking for manufacturers to make sure that a vaccine, once discovered, could be produced and delivered. It soon became clear, however, that all the manufacturers in wealthy countries with the capacity were either unwilling or unable to do it at a cost affordable by the countries that needed it. MVP was forced to rethink its strategy. An Indian manufacturer, the Serum Institute, said it could manufacture an inexpensive vaccine, but it needed additional support to do so. In response, MVP assembled a consortium of international partners to provide that support. For example, with the foundation’s help, a company from the Netherlands provided some of the basic components of the vaccine.

Serum Institute eventually put the pieces together and was able to develop MenAfriVac and sell it at the target price. Between 2010 and 2014, large-scale vaccination campaigns were begun in Burkina Faso, Mali, Niger, Cameroon, Chad, Nigeria, Benin, Ghana, Senegal, Sudan, the Gambia, and Ethiopia, and in 2014, MenAfriVac was added to routine immunizations schedules in sub-Saharan Africa. In areas where it has been introduced, meningitis outbreaks have completely disappeared.

Anti-virals have been an underinvested branch of science for a long time, including by our foundation. Researchers have not been as effective at developing drugs to fight viruses as they have been at developing those to fight bacteria. But that’s changing during COVID-19.

Our foundation has worked with many partners to pull together scientists, CEOs, and public health experts to test existing drugs against the novel coronavirus and make sure successful candidates get to everyone who needs them.

We’ve seen significant breakthroughs in this area. For example, pharmaceutical companies have agreed expand drug making capacity by using each other's factories. Remdesivir, for example, was created by Gilead, but extra quantities will now be produced in Pfizer factories. Very few companies have ever allowed its factories to be used by competitor in this way.

We expect to see more cooperation when it comes to lifesaving treatments in the future. We’re working with researchers will develop large, diverse libraries of antivirals, which they’ll be able to scan through to quickly find effective treatments if another new virus appears.

At the turn of the 21st century, three of the deadliest diseases in the world raged out of control, and the global health community was losing the fight against them. There were AIDS drugs available, but the majority of people in poor countries couldn’t afford them. Mosquitoes had developed resistance to the insecticides and the parasite had developed resistance to the treatments that had once kept the disease in check. A test that could reliably diagnose TB did not exist. It was clear that something needed to change. So in 2001, UN Secretary General Kofi Annan called for making the fight against these diseases a global priority; shortly thereafter, the UN announced the creation of the Global Fund to Fight AIDS, Tuberculosis, and Malaria, a new form of public-private partnership for global health financing.

This was a new way of doing global health: pooling funds to generate enough demand to lower the prices of drugs and other supplies and disbursing the money to countries that needed it.

Donor countries provide 92% of the funding, and the rest is contributed by the private sector and foundations. In 2001, the Gates Foundation became one of the first of those foundations with a gift of $100 million; since then, we have contributed more than $2 billion.

The Global Fund has been a huge success, allowing more than 100 countries to offer bed nets, AIDS treatments, TB tests, and other lifesaving solutions. Since its creation in 2002, the Global Fund has distributed over $45 billion to 155 countries, saving an astonishing 38 million lives and offering care, treatment, and prevention to hundreds of millions more.

The government has a vested interest in helping young Americans go to college. That’s why it offers the Free Application for Federal Student Aid (FAFSA), which opens up access to Pell Grants, Equal Opportunity Grants, the Federal Work-Study Program, and more.

But filling out the FAFSA is not an easy task, and many prospective students find it confusing and intimidating. As a result, every year as many as 2 million students who are eligible for Federal financial aid, many of whom come from low-income backgrounds or are the first in their families to attend college—simply don’t apply.

Eliminating one obstacle to a bright future doesn’t do much good if it’s replaced with another obstacle. That’s why, drawing on the work of partners through our Reimagining Aid Design and Delivery initiative, the foundation developed a road map for fixing the FAFSA. The goal is to guarantee that all students have access to financial aid and a high-quality, affordable postsecondary education.

The government has already implemented some of the report’s recommendations, and as of July 1, 2023, thanks to the recently passed FAFSA Simplification Act, students across America will face fewer barriers to college.

In early 2007, researchers developed a new vaccine to prevent pneumonia.

It cost $70 for a single injection of the vaccine in wealthy countries, which is expensive as vaccines go. Most people thought it wouldn’t be available in poorer countries for another decade or two – even though that’s where most pneumonia deaths happen.

But that year our foundation partnered with several governments and international organizations to try something new: We negotiated the first advance market commitment (AMC), putting up billions of dollars to finance vaccine makers like GSK and Pfizer as they scaled up production. This way, they could lower costs. We helped cut the price for the vaccine from $70 a dose, to $3.50, and it was rolled out immediately in poorer countries.

This marked a landmark transition in the history of global health. Kids in low-income countries were no longer getting the vaccines last. They were getting them at the same time as the kids in higher-income countries.

Sanitation-related diseases kill almost 500,000 children every year. Almost all of these children live in low-income countries without sanitation systems to safely contain and treat human waste.

Philanthropy can play a critical role in the development of such systems. The foundation’s Reinvent the Toilet Challenge, issued in 2011, sought designs for new toilets that could run without water, sewers, or electricity, that left waste 100% pathogen-free, and that cost no more than 5¢ per day per user. The response was overwhelming: we received over 120 concepts from scientists at universities across the world. Some concepts not only treated waste but also turned it into valuable resources such as electricity, ash for fertilizer, and small amounts of distilled water.

A total of 20 reinvented toilets were showcased in Beijing in 2018. Since then, many of these have been prototyped and piloted; the next step is to work with private companies so that these technologies can be scaled. Now that a portfolio of new toilet technologies is available, it is time for the private sector to do what it does best: build products people need and figure out how to bring them to markets around the world.

It’s hard to imagine, but until a decade ago, the United States had no reliable way to know how many students were graduating from high school. Each state calculated its graduation rate in a different way. Furthermore, respected researchers from noted institutions did their own calculations and found wide gaps between their figures and what many states reported.

Our foundation, along with partner organizations like the Data Quality Campaign, funded research to illustrate the problem, proposed solutions, and worked to implement them. In 2008, the U.S. Department of Education released new regulations requiring states to report a uniform, comparable, and accurate graduation rate.

Since the 2010-2011 school year, states have reported graduation rates according to the new regulations; almost immediately, a previously hidden problem was revealed—the disparate systems made it very hard to notice and catch extremely low graduation rates and, therefore, hard to do anything about them. Now that states’ reporting is uniform, educators have been able to tackle the issue head-on, and we can say with confidence that today the national high school graduation rate is at an all-time high: 85%.

Students of Summit Prep celebrate during graduation ceremonies in Redwood City, California.

We recently began a program to increase mobility from poverty and help more Americans climb the economic ladder to improve their lives. To start the work of helping people lift themselves out of poverty, we asked experts to help us separate myth from reality and provide the evidence about how much opportunity there actually is in America, who has it, and who doesn’t. The economist Raj Chetty had already published a study showing that children born in 1940 had a 90% chance of growing up to earn more than their parents, but that for children born 40 years later that chance had fallen to 50%.

We helped Chetty and his team start asking questions on an incredibly granular scale, learning about patterns of mobility not just in individual cities but even in individual neighborhoods and individual parts of individual neighborhoods. The result is a platform called The Opportunity Atlas that you can use to explore how much opportunity people in different places all over the country have—and, more importantly, that can help governments work to increase that amount.

The Atlas has already served as an advocacy and planning tool, by raising awareness of where and how much inequality there is. Chetty is now working to make it into a policy tool as well, so that in addition to information about what we need to change, it can also tell us what to do to start changing it.

How much income did women in developing countries earn last year? How much property do they own? How many more hours do girls spend on household chores than boys?

These are important questions. The answers can help policymakers make better decisions about where they direct funding. Unfortunately, no one knows the answers. No organization has ever collected the data that would make those numbers knowable.

When the SDGs were adopted in 2015, they included a goal explicitly about empowering women and girls, which was a powerful way to establish priorities and hold leaders accountable. But it’s a sign of how much this issue has been neglected that only three of the 14 indicators under the gender equality goal had sufficient baseline data and were trackable.

That’s why our foundation announced in 2016 that it would spend $80 million to close the gender data gap. When it is possible to quantitatively diagnose the challenges facing women and girls, set ambitious but realistic targets, track progress, and identify best practices, the development community will finally have the tools it needs to achieve gender equality.

Going to college in the United States is more expensive than ever—not just at the private four-year colleges where the tuition price tags garner headlines, but at public and two-year colleges as well. Students are naturally starting to wonder: Is college worth it?

The data is clear that students from low-income backgrounds and students of color are more likely to feel that it’s not worth it to them. A student from a high-income background is five times more likely than a student from a low-income one to have a bachelor’s degree by age 24. A white adult is twice as likely as a Hispanic adult to have at least an associate degree.

In 2019, the foundation, in partnership with the Institute for Higher Education Policy, launched the Postsecondary Value Commission, with the goal of clearly defining and then measuring value. The Value Commission’s research focuses on the impact of variables such as where students attend college, what they study, and whether they finish their credential on their earnings after college.

The fact is that almost every new job since the last recession—that’s 13 million jobs—has gone to someone with a postsecondary education. College is by far the best path to a well-paying job in today’s society, and it’s vital that every young person have equal access to that path. The Value Commission is making sure all students have the information they need to make the right choices, and educators have an incentive to provide their students—all their students—with routes to good jobs.